SACRAMENTO -- This Thursday the California Air Resources Board (ARB) will consider a plan to reduce statewide diesel
emissions by 90 percent within the next ten years. If adopted, the plan calls for a dozen separate control
measures that would require the use of low-polluting fuel, retrofits on existing engines and modifications on new engines
to reduce emissions. The plan includes proposals that address both motor vehicles and stationary source engines.

Diesel particulate matter (PM) emissions have been found to be the most pervasive toxic air contaminant (TAC)
in California, contributing about 70 percent of the health risk attributed to airborne toxic emissions.

In 1998 the Board identified diesel PM as a toxic air contaminant. Once a substance is identified as a TAC,
the ARB is required by law to determine if there is a need for further control. If additional controls are
deemed necessary, the Board must develop a risk management plan to protect public health.

The Air Resources Board is a department of the California Environmental Protection Agency. ARB's
mission is to promote and protect public health, welfare, and ecological resources through effective reduction
of air pollutants while recognizing and considering effects on the economy. The ARB oversees all
air pollution control efforts in California to attain and maintain health based air quality standards.